The present invention relates to an aqueous dispersion of polymer particles and thermosettable resin imbibed polymer particles suitable for use as a traffic paint.
Waterborne traffic coating compositions offer a low cost environmentally friendly way of improving roadway safety and communication to drivers, cyclists and pedestrians. U.S. Pat. No. 5,527,853 discloses a shelf stable quick-setting waterborne formulation suitable for traffic paint comprising an acrylic latex, a polyamine, and a volatile base. The formulation is disclosed as being storage stable, even at advanced temperatures.
U.S. Pat. No. 5,939,514 discloses a waterborne latex formulation comprising a) an acid stabilized binder blended with a polyamine or functionalized with amine groups; b) a crosslinking component; and c) a volatile base. This formulation is reported to give a coating with improved wear resistance as compared with formulations that do not contain a polyamine and a crosslinking component. Nevertheless, the formulation requires relatively high concentrations of an expensive crosslinker (for example >20% epoxy resin based on latex solids), which reduces the window of time available to the formulator to apply the coating to the substrate once the binder/polyamine/volatile base is blended with the crosslinker (pot life).
Accordingly, there is a need in the art to find a cost effective, quick setting waterborne formulation with improved pot life that forms a durable pavement marking.